Glycosyl composition analysis was performed on Ehrlichia risticii lipopolysaccharides. The samples were analyzed for monosaccharide composition by preparing the trimethylsilyl derivatives of the methylglycosides followed by gas chromatography (GC) and combined gas chromatography/mass spectrometry (GC-MS) analysis. TMS methylglycosides were prepared from the sample by methanolysis in 3 M HCl followed by N-acetylation with pyridine and acetic anhydride. The samples were then treated with Tri-Sil. GC analysis of the TMS methylglycosides was done on an HP5890 GC using a DB1 fused silica capillary column. GC-MS analysis was performed using an HP5890 GC coupled to a 5970 MSD. Monosaccharides were identified by their retention times in comparison to standards, and the carbohydrate character of these was authenticated by their mass spectra.